Quantum Control of Chaos inside a Cavity

By sending many two-level atoms through a cavity resonant with the atomic transition, and letting the interaction times between the atoms and the cavity be randomly distributed, we end up with a predetermined Fock state of the electromagnetic field inside the cavity if we perform after the interaction with the cavity a conditional measurement of the internal state of each atom in a coherent superposition of its ground and excited states. Differently from previous schemes, this procedure turns out to be very stable under fluctuations in the interaction times.